Guess It's Not So Perma After All

Melting Siberian permafrost could release billions of tons of CO2

As it melts, Siberian permafrost could release up to 500 billion tons of carbon dioxide from ancient plant roots and animal bones into the atmosphere -- twice what scientists had previously expected, says a new study in Science. It's a (woolly) mammoth amount: at present, the atmosphere contains about 800 billion tons of greenhouse gases, and human fossil-fuel burning adds roughly another 6.5 billion tons of CO2 a year. The study, conducted by Russian and American researchers, warned of the possibility of a cyclical effect: warming causes melting, which causes more warming, and so on. "I'm a scientist, so we tend to be conservative in our language. But I would say this could make global warming significantly worse" than expected, said study coauthor Ted Schuur.